AAOS2013：成人脊柱畸形矫正术后临近节段失败的风险因素

引言：临近节段失败（proximal junctional failure, PJF）包括后凸和其它骨及韧带结构的异常，并不等同于临近节段后凸（proximal junctional kyphosis, PJK），是成人脊柱畸形（ASD）矫形手术后的严重并发症，多有疼痛、不稳、神经损伤而需要再手术。本研究拟对此种并发症的风险因素进行评估。
方法：对因ASD进行手术而出现PJF并再手术者进行多中心病例对照研究，PJF的定义：内固定装置顶端椎体（upper instrumented vertebra, UIV）及其上端两节椎体（UIV+2）后凸角度较术前增加10度以上；UIV或UIV+1骨折；脱位或内固定失败。将PJF患者与非PJF（NOPJF）患者进行配对，配对原则参考融合节段数和UIV。根据UIV进行分组：胸腰段（TL；UIV=T9-T11）或上胸椎（UT；UIV=T2-T5）。认为可能的风险因素包括：年龄、矢状平衡（sagittal vertical axis, SVA），胸椎后凸（thoracic kyphosis, TK），腰椎后凸（lumbar lordosis, LL），骨盆投射角（pelvic incidence）减去腰椎前凸（PI-LL）以及骨盆倾斜（pelvic tilt, PT）。对两组患者一般资料、术前影像学参数、矢状位参数变化的测量值进行多元方差分析。
结果：TL组中PJF(n=37)与NOPJF(n=21)的组间差异分别表现在年龄(59.2：43.7岁), 术前TK (40.5°：29.6°), 术前LL (18.8°：43.6°), 术前PI-LL (35.9°：17.5°)和LL变化 (30°：9.6°), (p<0.05)。UT组中PJF(n=15)和NOPJF(n=33)差异表现在年龄(67.8：59.5 years), 术前SVA (68.3：1.6 mm), 术前PT (26.8°：17.5°), 术前PI-LL (19.2°：0.61°), 术前TK (55.2°：33.7°)和SVA变化 (69：49 mm), (p<0.05)。PJF患者中行PSO者更多(29%：6%)，UT组中PJF患者较对照组融合至骶骨的患者更多(73.3%：39.4%), (p<0.05)。PJF者行翻修手术的机率更大(TL 35%：9%; UT 67%：18%; p<0.05)。
讨论和结论：本病例对照研究的结果表明，对因ASD进行手术的患者来说，PJF的危险因素包括：年龄、矢状面畸形、矢状面矫形手术、PSO和融合至骶骨。出现PJF者多需要进行翻修手术，因此，对于以上危险因素在手术规划时应加以关注。

与脊柱相关的拓展阅读： 

• AAOS2013：动静态脊柱滑脱的影像学分析
• Arthritis Care Res：早期强直性脊柱炎患者功能障碍更易受放射学损害影响
• ACR：早期强直性脊柱炎患者功能障碍与放射学损害相关性更强
• 部位不当脊柱手术漏报问题的调查
• Neural Regen Res.：脊柱图像引导放疗有助于保护脊髓神经元 更多信息请点击：有关脊柱更多资讯

Age, Sagittal Balance and Operative Correction are Risk Factors for Proximal Junctional Failure in Adult Deformity
INTRODUCTION
Proximal junctional failure (PJF) is distinct from proximal junctional kyphosis (PJK), and includes kyphosis and osseoligamentous failure. PJF is a potentially catastrophic complication following adult spinal deformity (ASD) surgery. PJF patients are at risk for pain, instability, neurological injury and need for revision surgery. We evaluated risk factors for clinically significant PJF following ASD surgery.
METHODS
Multi-center, case-control analysis of consecutive ASD patients suffering PJF following surgery. PJF was defined as kyphosis increase > 10° from upper instrumented vertebra (UIV) to two levels above (UIV+2) from pre-op value, and UIV or UIV+1 fracture, dislocation or implant failure. PJF patients were matched controls without PJF (NOPJF) from a prospective ASD database. Matching criteria were levels fused and UIV. The groups were divided by level of UIV: thoracolumbar (TL; UIV=T9-T11) or upper thoracic (UT; UIV=T2-T5). Potential risk factors included: age, sagittal vertical axis (SVA), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence minus lumbar lordosis (PI-LL) and pelvic tilt (PT). Differences in demographic variables, pre-op radiographic parameters and measures of surgical sagittal realignment between PJF and NOPJF groups were analyzed using a multi-variate ANOVA.
RESULTS
TL group differences between PJF (n=37) and NOPJF (n=21) included age (59.2 vs. 43.7 years), pre-op TK (40.5° vs. 29.6°), pre-op LL (18.8° vs. 43.6°), pre-op PI-LL (35.9° vs. 17.5°) and change in LL (30° vs. 9.6°), respectively (p<0.05). UT group differences between PJF (n=15) and NOPJF (n=33) included age (67.8 vs. 59.5 years), pre-op SVA (68.3 vs. 1.6 mm), pre-op PT (26.8° vs. 17.5°), pre-op PI-LL (19.2° vs. 0.61°), pre-op TK (55.2° vs. 33.7°) and change in SVA (69 vs. 49 mm), respectively (p<0.05). PSO was more common in all PJF patients (29% vs. 6%) and more UT PJF patients were fused to pelvis than NOPJF (73.3% vs. 39.4%), respectively (p<0.05). Revision surgery was performed more frequently for PJF than NOPJF (TL 35% vs. 9%; UT 67% vs. 18%; respectively; p<0.05).
DISCUSSION AND CONCLUSION
This case-control analysis of ASD surgical patients demonstrated that risk factors for PJF include age, sagittal deformity and sagittal correction. PSO and fusion to pelvis are also risk factors. Given the more frequent need for revision surgery among patients experiencing PJF, efforts to identify methods to prevent this complication are warranted.